Patuxent River Appreciation Days (PRAD) is a festival, which creates awareness, recognition, and promotion of the economic, social, recreational, cultural and historical impact of the tributaries and environs of the Patuxent River and the basin through which it flows. The festival has been held annually on Columbus Day weekend since 1978.

The festival brings together, and reflects the continuing commitment of the community, Calvert County Commissioners, the Calvert Marine Museum, and other organizations which share a desire to preserve the Patuxent River and to celebrate its positive influence on the area's quality of life, in the past, present and the future.

By bringing these people together in public forum annually, PRAD hopes to continue the interest in the support of the environmental programs and tourism activities surrounding the Patuxent River and its tributaries.